I've recently upgraded from an old PWM charge controller to an MPPT model in my campervan, but I'm feeling pretty frustrated. Despite sunny conditions (maybe just a little wispy cloud), I'm only getting 12 volts from the solar panel into the MPPT charge controller, which is preventing me from charging my leisure battery. Is there something I'm overlooking? My solar panel should produce over 25 volts open circuit, and it's rated at around 80 watts. The MPPT I'm testing is the Epever Tracer 2206AN, and when I check the readings, it shows 0.0A with no load connected and indicates 0.5kWh, which seems odd since that number appears even when the PV is disconnected. The battery reads 12.5 volts. Shouldn't I be getting at least some charge with decent sunlight?
4 Answers
Honestly, with an 80 watt panel, you shouldn’t expect a load of power. If you're looking for better performance, save up for additional solar panels. However, it's reasonable to see at least some charge under good sunlight—even a little should be manageable!
First, it’s a good idea to measure the actual voltage being output from your solar panels with the wires connected to the MPPT. You mentioned that open circuit voltage is over 25 volts, but when you connect it, you're only seeing 12 volts. That’s definitely a red flag—maybe there’s a voltage drop happening somewhere in the connections?
You should check the voltage at maximum power point (Vmp) of your panel. You said it’s around 21.12 volts, which is pretty standard for an 80w panel. Also, make sure there aren't any damages to the panel or wiring. A poor connection at the panel end could also lead to such issues, but since you've fixed that, it might just be limited performance from the panel itself.
If everything seems fine but you’re still not getting the output, it might be worth considering investing in additional solar panels to get the most out of the MPPT.
Yeah, measuring with load connected is key. It could be a wiring issue if there’s a significant drop.